textproduct: Rapid City

KEY MESSAGES

- A Wind Advisory continues for tomorrow with northwest winds gusts from 45-55 MPH on the western SD plains. - Near-critical to critical fire weather conditions Wednesday. - Better chances for precipitation this weekend.

UPDATE

Issued at 1031 PM MDT Tue Jun 16 2026

04z surface analysis had elongated low pressure from central ND through eastern CO. Water vapour loop had upper low over central Canada with northwest flow aloft spinning a series of shortwaves through the northern Plains. Latest wave affecting the Dakotas with shra/TS this evening, tapping into limited buoyancy as echoes zip southeast at 55 MPH.

Going forecast in pretty good shape. Behind a cold front later tonight, expect 30-45kt boundary layer winds to develop, mixing out in the morning on the SD plains. Wind gusts to 55 MPH likely given forecast Bufkit soundings, latest MOS, and NBM guidance (60-90% chance 50+ MPH gusts).

Rest of forecast left largely intact with wetter/cooler pattern chances increasing for the weekend.

DISCUSSION

(This Evening Through Tuesday) Issued at 135 PM MDT Tue Jun 16 2026

A low pressure system spinning near the west side of the Hudson Bay is our main weather maker for the short term forecast. It's giving the CWA northwest flow with just enough upward vertical motion to get some showers and thunderstorms going in the upper great plains. So far, most of the activity has been contained to eastern SD while the western counties have been dry for the most part, save for a few cells that have been short-lived.

Looking ahead to tonight through tomorrow night, continued northwest flow will keep the chances for isolated showers and non- severe thunderstorms to track into the area from the north. These chances will be mainly centered around little shortwaves spinning around the main low that will keep spinning near Hudson Bay. Temps tonight will dip into the 50s to mid 60s and tomorrow's highs will be mostly in the 70s. The exceptions are the far northwest SD counties and the far southern SD counties where temps will reach the upper 60s and near 80 respectively. NE WY looks to reach the low to mid 70s.

Tomorrow's winds will be the main story though. Strong northwest winds at 15 to 30 mph with gusts nearing 45 to 55 are likely Wednesday afternoon. Strongest winds will be in the SD plains. There is some evidence that gusts to 60 mph are possible in the NW SD plains but not enough to warrant issuing a High Wind Warning at this time, so decided to go with a high-end Wind Advisory. Will update if needed.

Thursday will continue the chances for isolated showers and storms from the northwest with the cooler highs in the 70s. A big difference will be the calmer winds with expected northwest winds at around 10 to 20 mph with gusts nearing 30 mph.

Friday and the weekend will see the weather pattern change to a more westerly flow. This will bring back warmer temps and more widespread thunderstorm chances for the weekend.

AVIATION

(For the 06Z TAFS Through 06Z Wednesday Night) Issued At 1040 PM MDT Tue Jun 16 2026

Mainly VFR conditions are expected through the forecast period. Very gusty northwest winds will pick back up with earnest early Wednesday morning behind a cold front. Gusts up to 45kt will occur on the western SD plains for the daytime period on Wednesday, slowly diminishing Wednesday night. Isolated to scattered showers and thunderstorms will affect northwestern SD overnight through the day on Wednesday, with local MVFR/IFR conditions associated with storms.

FIRE WEATHER

Issued At 135 PM MDT Tue Jun 16 2026

A cold front will move through early Wednesday morning. Behind the cold front, strong northwest winds from 25 to 35 mph with gusts from 40 to 55 mph are expected. Minimum relative humidity values will dip as low as 18 percent, which is higher than normal (<=15%) thresholds. However, the strong winds will make up the difference as well as antecedent D2 to D3 drought and very dry weather over the past 1-2 weeks. Thus, critical fire weather conditions are expected for parts of northeastern Wyoming and southwestern South Dakota late Wednesday morning through the early evening hours.

Humidities on Thursday and Friday will bottom out in the 20s with winds gusting to 15 to 30 mph. Elevated to near-critical fire weather conditions will continue as a result.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 6 AM to 8 PM MDT Wednesday for SDZ001-002-012- 013-025-072-073-078. Wind Advisory from 9 AM MDT /10 AM CDT/ to 8 PM MDT /9 PM CDT/ Wednesday for SDZ014-026-027-030>032-041>044-046-047-049- 074>077. Red Flag Warning from 11 AM to 8 PM MDT Wednesday for SDZ321-322- 325-326-332-333. WY...Red Flag Warning from 11 AM to 8 PM MDT Wednesday for WYZ315-317.